All music lovers have at least one album in their collection that they know all the words to (including all the backup vocals), just like movie buffs have that one DVD that seems to spend more time in the player than it does in its case. It’s these titles that initiate fans into that special group that loves that content to death. While these titles aren’t always traditional cult classics, their followings have become cult-like over time. Here, we explore just a handful of these titles and how they’ve continue to engage us well years after their initial release.

MUSIC MUST HAVES

When English rockers Pink Floyd first released Dark Side of the Moon in 1973, they probably couldn’t have imagined how popular it would become over time. Today, four decades after its release, it continues to sell an average of more than 3,000 units a week. And during the week of its 40th anniversary, it sold over 19,000 copies. The same goes for the Beatles’ 11th studio album, Abbey Road. Originally released in September of 1969, this pop classic continues to sell an average of 1,500 albums a week, while the top track “Here Comes The Sun,” continues to sell approximately 2,500 tracks a week.

Bob Marley and the Wailers’ 12th album Legend lives up to its name, having sold more than 11 million records in the U.S. to date. This year alone, it continues to sell an average of over 4,000 records each week. Michael Jackson’s Thriller isn’t just for Halloween—music fans continue to buy an average of 3,000 albums a week, even 30 years after its original release. These titles aren’t just timeless because of the legacies and personalities of the artists behind them. They’re legendary compositions that people continue to enjoy many years later. They’ve also gone on to become some of the best-selling albums of the past two decades.

CHILDHOOD AND CLASSROOM CLASSICS

Our obsession with content starts at a very young age. And while the phrase cult classic isn’t typically used to describe kids’ picture books, it’s actually very applicable.

The books and picture books that we read in our youth are special to us because we’re exposed to them when we’re most impressionable. They’re also special to retailers, as picture books like Goodnight Moon, Love You Forever, and Brown Bear, Brown Bear, What Do You See? have all landed on bestseller charts.

Goodnight Moon, by Margaret Wise Brown (first published in 1947), is one of the oldest pictures books on record and continues to sooth generations of munchkins to sleep more than half a century later. It sold nearly 7,500 print titles the week ending Oct. 20, 2013, while Love You Forever, by Robert N. Munsch (first published in 1986), sold over 5,700 physical titles during the same week. Also, originally published in 1967, Brown Bear, Brown Bear, What Do You See?, by Bill Martin Jr. and Eric Carle sold more than 6,000 units of the print title the same week—proof that required reading starts at a very young age.

When we look at literary classics like To Kill a Mockingbird and The Great Gatsby, it’s clear that their authors had a talent for creating works that would engage readers for decades. Copies of Harper Lee’s To Kill a Mockingbird, first published in 1960, sold more than 6,000 print copies in the week ending Oct. 20, 2013. Meanwhile The Great Gatsby, originally published in 1925 by F. Scott Fitzgerald sold over 5,700 print books during the same week ending Oct. 20, 2013. The book also remains a literary classic used in academia, as it was used in more than 1,000 colleges in the 2012-2013 academic year, prompting sales of 16,000 copies at university bookstores.

This summer’s film adaptation of Fitzgerald’s tale about the young and mysterious Jay Gatsby has helped spark renewed interest in this classic. The film release (May 10, 2013) likely spiked book sales, ultimately pushing the title to the No. 3 spot on the top 10 overall best-selling titles the week ending May 19, 2013. And that popularity—along with the star power of leading man Leonardo DiCaprio—has helped the film as well. The movie title, despite only being released Aug. 27, 2013 has already sold 885,000 discs to date.

GRAPHIC NOVEL INSPIRATION

Anyone who has been to Comic-Con is well aware of the great lengths fans will go to show their excitement for their favorite superheroes. And that level of enthusiasm has been a boon for publishers of the array of movie franchises that began as graphic novels. Marvel’s The Avengers (released April 2012) had sold over 7.7 million DVD and Blu-ray discs combined to date as of week ending Oct. 13, 2013. Thor, released September 2011, has also proven to be a home entertainment favorite, selling more than 3 million disc units to date. And then there’s Batman, one of the most enduring comics on the big screen. The most recent trilogy, Batman Begins (2005) The Dark Knight (2008) and The Dark Knight Rises (2012), continue to entice home entertainment fans, with the final installment selling over 5.8 million discs since its release.

BRING ON THE BOOK FRANCHISES

And no book-to-movie discussion would be complete without including Harry Potter. The books in the series have sold 516,000 physical units to date, and disc sales have been solid post theatrical release as well. When looking at the most recent disc releases, Harry Potter and the Deathly Hallows Part 1 has garnered 5.2 million discs sold in full (over 84,000 year to date), while Part 2 has sold 4 million discs to date (over 154,000 year to date).

Sci-fi book Ender’s Game, by Orson Scott Card, was originally released in 1985. The title sold 22,000 physical units through the one week ending Oct. 20, 2013, potentially as interest rises with the movie adaptation to be released Nov. 1, 2013. And just in time for Halloween, a new remake of Stephen King’s Carrie hit theaters on Oct. 18, 2013. With Carrie hitting the screens again, the title sold over 5,000 print book units the week ending Oct. 20, 2013.

These titles may have started as cult classics, but the strong devotion of fans has elevated their popularity to heights never originally imagined. What makes them classics? It’s an enduring momentum that continues to build as legions of fans keep them in heavy rotation and the entertainment industry finds new ways to tell their timeless tales.